1). Field of the Invention
This invention relates to a microelectronic die having a thermoelectric module and to an electronic assembly which includes such a microelectronic die.
2). Discussion of Related Art
Microelectronic circuits are usually formed in rows and columns over a silicon or other semiconductor wafer substrate. The silicon substrate is subsequently “singulated” or “diced” by directing a blade of a saw in x- and y-directions between the dies to separate the dies from one another. Such a die is then typically mounted to a carrier substrate for purposes of providing rigidity to the die and to provide signals, power, and ground to the die.
In certain applications, the microelectronic circuit is formed on a front side of the die, and solder balls or other conductive members are formed on the front side of the die. Such a die is located with the front side thereof facing the carrier substrate, and attached to the carrier substrate in a thermal reflow process. A thermally conductive plate of an integrated heat spreader or a heat sink is then located against a back side of the die with a thermal interface material coupling the back side of the die to the thermally conductive plate. The purpose of the thermally conductive plate is to provide a path through which heat can conduct from the die.
Passive cooling with heat sinks and thermally conductive plates no longer provides sufficient cooling because (a) the magnitude of power generated by microelectronic circuits of some dies has become so high; (b) power density of some areas of a die has become very high; and (c) a thermally conductive plate is relatively far from the microelectronic circuits, so that a thermal resistance and/or a thermal spreading resistance are created by silicon and other materials between the microelectronic circuit and the thermal conductive plate. Existing cooling solutions furthermore do not provide the capability of localized cooling of hot spots of a die. Thus, an active, refrigeration-based cooling may be required.